With continuous development of technology, fingerprint recognition technology has been widely used in smart terminals for users' identity verification. At present, the fingerprint recognition technology of smart terminals mostly uses a serial peripheral interface (SPI) of a fingerprint sensor to send a capacitance or inductance signal formed between a finger surface and a fingerprint detection panel to a processor. The processor generates a fingerprint image according to the capacitance or inductance signal, and the fingerprint recognition is realized according to the fingerprint image.
For example, when the smart terminal enters the standby and fingerprint unlocking interface, the SPI is in an opening state, waiting to transmit the signal.